1. Field of the Invention
An object of the the present invention is a device for interconnection between an integrated circuit (markded IC) and an electrical circuit (marked EC) such as, for example, a printed circuit (marked PC), the EC having a face that is substantially parallel to the active face of the IC. The device is capable of connecting at least one contact zone of the IC and one connection point of the EC, which are offset with respect to one another in an abstract plane (called a "reference" plane) substantially parallel to the active face of the IC. Thus, whatever may be the correspondence desired between the contact zones of the IC and the connection points of the EC, the device enables a substantial reduction in the number or the length of the tracks made, in or on the IC or the EC, through a judicious choice of displacements, in the reference plane, within the device itself, it being possible to program a choice such as this. Another object of the invention is a device for the fabrication of a part of this device using a previously fixed number of modules of only one type.
The relative dimensions of the contact zones of an active face of an IC and of the connection points of an EC, such as, for example, a single-layer or multiple-layer PC, exclude the possibility of directly connecting the IC to the EC: it is necessary to interconnect the IC and the EC by means of a device with a fineness of connection in between that of the IC and that of the EC. A device of this type necessarily takes up space and complicates the manoeuvre wherein the interconnection is done.
Furthermore, the desired correspondence between the contact zones of the IC and the connection points of the EC may imply the making of additional tracks.
2. Description of the Prior Art
There are known devices for interconnection between an IC and an EC, comprising a base fabricated from an insulating material, located between the IC and the EC. The dimensions of this base, in said reference plane, are far greater than those of the IC to which is fixed the IC on the side opposite to its active face. The desired interconnection is provided by means of electrical conducting wires (called "bonding wires", the fineness of which is of the same magnitude as that of the contact zones of the IC) connecting the contact zones of the IC to electricity conducting tracks (the fineness of which is in between that of the contact zones of the IC and that of the connection points of the EC) which are made on and/or within the base, said tracks diverging around the IC, for example towards pins, which are designed to be plugged into holes of a PC. There is also a known arrangement where a base such as this is provided not with pins but with contact zones placed on the periphery of the face of the base located before the EC, connected to said tracks, for example, by means of a partial metallization of the sides of the base, and designed to be soldered to the connection points of the EC.
These known devices, however, have a great many drawbacks:
because of their fineness, the bonding wires are brittle. To reduce this brittleness to the minimum, these wires are as short as possible, and only reach places located on the periphery of the active face of the IC (in other words, the contact zones of the IC are peripheral): this firstly restricts the number of contact zones of an IC with a given area and, secondly, implies the making of track (in and/or on the IC) connecting the zones located at the center of the active face of the IC with its periphery; PA0 again because of their fineness, the bonding wires are difficult to connect, both to the contact zones of the IC and to the tracks of the base; PA0 the bonding wires are connected one by one, and this takes time; PA0 since the dimensions of the base in the reference plane are greater than those of the IC, the interconnecting device is bulky; PA0 this interconnection device cannot be used to compensate for any complexity of the correspondence desired between the contact zones of the IC and the connection points of the EC. PA0 assembling means providing for electrical contact between the contact zones of the IC and the contact zones of said first face, on the one hand, and between the contact zones of said second face and the connection points of the EC on the other hand, PA0 the contact zones of said platelet have a size between that of the contact zones of the IC and that of the connection points of the EC, PA0 said internal means provide for an electrical contact with a pre-determined number of electricity conducting channels, going through the platelet without any offset, and a pre-determined and non-zero number of electricity conducting channels going through the platelet with an offset in an abstract plane of reference substantially parallel to the active face of the IC, said offfset taking place in a pre-fixed direction within one and the same platelet.